如何杀死所有postgresql连接？
我正在尝试rake db:drop但是我得到了:
ERROR: database "database_name" is being accessed by other users
DETAIL: There are 1 other session(s) using the database.
我已经尝试关闭我从a看到的进程,ps -ef | grep postgres但这也不起作用:
kill: kill 2358 failed: operation not permitted
使这些标签持续存在的最佳方法是什么？
http://twitter.github.com/bootstrap/javascript.html#tabs
要添加一些上下文,这适用于rails应用程序.我将一个数组[tab1,tab2]传递给我的视图,渲染两个选项卡并使用引导选项卡插件切换其可见性.
任何人都知道运行时导致此错误的原因是什么cucumber features？
uninitialized constant DatabaseCleaner (NameError)
我正在尝试执行查找最接近current_user的记录的订单查询.
我知道这两点之间的距离是: current_location.euclidean_distance(@record.position)
如何将其用于PostGIS(或active_record/spatial_adapter)查询？
当我给出命令"rails s"以下错误时,请帮助我!我仍然在rails项目中,然后给出这个命令
root@ubuntu:~# cd mon
root@ubuntu:~/mon# rails s
/usr/lib/ruby/gems/1.8/gems/execjs-1.3.0/lib/execjs/runtimes.rb:50:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)
from /usr/lib/ruby/gems/1.8/gems/execjs-1.3.0/lib/execjs.rb:5
from /usr/lib/ruby/gems/1.8/gems/coffee-script-2.2.0/lib/coffee_script.rb:1:in `require'
from /usr/lib/ruby/gems/1.8/gems/coffee-script-2.2.0/lib/coffee_script.rb:1
from /usr/lib/ruby/gems/1.8/gems/coffee-script-2.2.0/lib/coffee-script.rb:1:in `require'
from /usr/lib/ruby/gems/1.8/gems/coffee-script-2.2.0/lib/coffee-script.rb:1
from /usr/lib/ruby/gems/1.8/gems/coffee-rails-3.2.2/lib/coffee-rails.rb:1:in `require'
from /usr/lib/ruby/gems/1.8/gems/coffee-rails-3.2.2/lib/coffee-rails.rb:1
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler/runtime.rb:68:in `require'
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler/runtime.rb:68:in `require'
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler/runtime.rb:66:in `each'
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler/runtime.rb:66:in `require'
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler/runtime.rb:55:in `each'
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler/runtime.rb:55:in `require'
from /usr/lib/ruby/gems/1.8/gems/bundler-1.1.3/lib/bundler.rb:119:in `require'
from /root/mon/config/application.rb:7
from /usr/lib/ruby/gems/1.8/gems/railties-3.2.3/lib/rails/commands.rb:53:in `require'
from /usr/lib/ruby/gems/1.8/gems/railties-3.2.3/lib/rails/commands.rb:53
from /usr/lib/ruby/gems/1.8/gems/railties-3.2.3/lib/rails/commands.rb:50:in `tap'
from /usr/lib/ruby/gems/1.8/gems/railties-3.2.3/lib/rails/commands.rb:50
from script/rails:6:in `require'
from script/rails:6
在Clojure(/ Java)中表示国际象棋比特的一些可能方法是什么？
http://pages.cs.wisc.edu/~psilord/blog/data/chess-pages/rep.html
我需要能够访问各个位并执行按位操作.
我想过使用java.lang.Long,但由于标牌,这导致了1x10 ^ 63的问题.我也不确定如何在特定索引处访问位？
我也看了BitSet,但理想情况下我需要一个固定的长度.
在我的项目中,我使用multiprocessing该类来平行运行任务.我想要使用threading,因为它具有更好的性能(我的任务是TCP/IP绑定,而不是CPU或I/O绑定).
multiprocessing有精彩的功能,Pool.imap_unordered并且Pool.map_async,不会在存在threading阶级.
将代码转换为使用的正确方法是什么threading？该文档介绍了multiprocessing.dummy该类,它是该类的包装器threading.但是这会引发很多错误(至少在python 2.7.3上):
pool = multiprocessing.Pool(processes)
File "C:\python27\lib\multiprocessing\dummy\__init__.py", line 150, in Pool
return ThreadPool(processes, initializer, initargs)
File "C:\python27\lib\multiprocessing\pool.py", line 685, in __init__
Pool.__init__(self, processes, initializer, initargs)
File "C:\python27\lib\multiprocessing\pool.py", line 136, in __init__
self._repopulate_pool()
File "C:\python27\lib\multiprocessing\pool.py", line 199, in _repopulate_pool
w.start()
File "C:\python27\lib\multiprocessing\dummy\__init__.py", line 73, in start
self._parent._children[self] = None
AttributeError: '_DummyThread' object has no attribute '_children'
编辑:实际发生的是我有一个运行不同线程的GUI(以防止GUI被gettint卡住).该线程运行具有ThreadPool失败的特定搜索功能.
编辑2:错误修复 …
任何人都可以告诉我一些工作依赖关系来启动和运行zeromq和clojure？
我试了好几个,但leiningen无法取得它们:
(无法org.zmq:zmq:jar:2.1.0在中央找到工件(http://repo1.maven.org/maven2))
[org.zmq/zmq "2.1.0"]
[org.zmq/jzmq "1.0.0"]
我编译了jzmq(/usr/local/share/java/jzmq.jar)并将其添加到我的project.clj:
:native-path "/usr/local/lib"
我希望我的门卫视图使用应用程序布局:
https://github.com/applicake/doorkeeper/wiki/Customizing-views
它包含主应用程序中的路由和辅助方法.
对于路由,我可以将main_app添加到路径前面,但是对于帮助器方法,我得到以下错误:
undefined method `is_active?' for #<ActionDispatch::Routing::RoutesProxy:0xade808c>
<li class="<%= main_app.is_active?("high_voltage/pages", "api") %>"><%= link_to t('developers'), page_path('api') %></li>
为什么是这样？帮助者在app/helpers/application_helper.rb
嗨,我是编程世界的初学者,我想知道如何避免更改const变量的值.
#include <stdio.h>
int main()
{
const int i = 10;
int * p = &i;
*p = 20;
printf("*p = %d\ni = %d\n", *p,i);
printf("%u\n%u\n",&i, p);
return 0;
}
在上面的程序中,我只得到警告但没有错误,而我通过指针将值分配给const字段,但是当我打印输出时没有不同:
*p = 20
i = 10
3210723532
3210723532
那么当它不能改变时,获取指向const的指针有什么用呢？